Conventional types of transistor include a bipolar transistor in which two p-n junctions each between semiconductors are combined, a junction-type field effect transistor (FET) in which a p-n junction is formed as a gate G between a source S and a drain D, a MIS (MOS) type FET in which an insulating thin film (oxide film) is formed on a surface of a semiconductor located between a source S and a drain D and a gate G is formed on it, and an electrostatic induction type of transistor (SIT) in which a gate length of the junction type FET described above is substantially reduced and for this reason channel potentials at a gate position can be controlled. In a bipolar transistor, a junction current flowing through the p-n junction is used, but generally a tunnel current is not used for its operations, nor is provided an insulating gate therein. Also when an electric current is caused to flow in FET or SIT, a channel for the current presents an identical conduction type, and a barrier causing a tunnel current to flow therethrough is not formed. The most important object in manufacturing switching transistors is to produce compact ones having a high processing speed, yet consuming only a small quantity of power. In the bipolar transistor, the base width essentially decides the processing speed, and if the base width is reduced excessively, a transistor effect is not provided due to the Early effect. In the FET, the gate length basically decides the processing speed, and the channel resistance as well as the gate capacity causes some problems to be solved. In case of SIT, the size can be reduced and a high processing speed is provided, but an advanced technology is required to bury the gate electrode. For the reasons as described above, development of a compact and high speed transistor having a large input impedance and consuming only a small quantity of power which can be used in a switching circuit has been desired. The present applicant already invented the "Schottky tunnel diode"(See the Japanese Patent Application No.320565/1991), but the diode has two terminals and is not equipped with a control function.